John Tedesco

New documents offer more information about the retaining wall that collapsed at the Hills of Rivermist, a neighborhood in San Antonio built by Centex Homes. Comparing the wall’s engineering plans to a memo describing how the wall was actually built shows the retaining wall might have lacked crucial features:

The memo was posted on a city Web page set up to provide daily updates about Rivermist. The city posts new information at the end of every business day.

Jen and I wrote a follow-up story today about the sinking neighborhood in San Antonio called the Hills of Rivermist:

The retaining wall that collapsed last week and jeopardized a neighborhood built by Centex Homes was built with less mortar than what engineering plans called for, according to city officials who inspected the wall Friday.

“Staff determined that the retaining wall was not built in accordance with the design provided by (the) design engineer,” Assistant City Manager T.C. Broadnax wrote in an e-mail to his boss, Sheryl Sculley, Mayor Julián Castro and the City Council.

“For example, the building plans for the wall show limestone mortared throughout the wall. Based on field observations of the failed portion of the wall, mortar was not installed according to the building plans.”

There are many different types of retaining walls. The one at Rivermist is called a gravity wall, which relies on a heavy mass of mortar and stones to remain stable. So if a contractor skimps on the mortar in the core of the wall, the wall becomes lighter and it can become unstable.

Here’s the city e-mail describing the lack of mortar inside the wall. The city also set up a new Web page that provides updates about Rivermist. Residents can also report concerns about retaining walls near their homes.